test: Additional Transaction tests and AggregationQuery test (#1518)

* test: ReadWrite Transaction test

* test: Added test for Transactional RunQuery and Transaction Rollback

* test: runInTransaction API tracing test
- Fixed setting of common span attributes to spans in runInTransaction
- Removed some gRPC related channel attributes that are not present in this Datastore version, yet.

google-cloud-datastore/src/main/java/com/google/cloud/datastore/DatastoreImpl.java

@@ -157,7 +157,7 @@ private io.opentelemetry.api.trace.Span startSpanWithParentContext(
                       .with(
                           io.opentelemetry.api.trace.Span.wrap(
                               parentSpanContext.getSpanContext())));
-      return spanBuilder.startSpan();
+      return otelTraceUtil.addSettingsAttributesToCurrentSpan(spanBuilder).startSpan();
     }
 
     @Override
@@ -540,7 +540,10 @@ com.google.datastore.v1.LookupResponse lookup(
                     .put("Received", response.getFoundCount())
                     .put("Missing", response.getMissingCount())
                     .put("Deferred", response.getDeferredCount())
-                    .put("isTransactional", isTransactional)
+                    .put("transactional", isTransactional)
+                    .put(
+                        "transaction_id",
+                        isTransactional ? readOptions.getTransaction().toStringUtf8() : "")
                     .build());
             return response;
           },
@@ -772,6 +775,11 @@ public Void call() throws DatastoreException {
           retrySettings,
           EXCEPTION_HANDLER,
           getOptions().getClock());
+      span.addEvent(
+          com.google.cloud.datastore.telemetry.TraceUtil.SPAN_NAME_ROLLBACK,
+          new ImmutableMap.Builder<String, Object>()
+              .put("transaction_id", requestPb.getTransaction().toStringUtf8())
+              .build());
     } catch (RetryHelperException e) {
       span.end(e);
       throw DatastoreException.translateAndThrow(e);

google-cloud-datastore/src/main/java/com/google/cloud/datastore/telemetry/DisabledTraceUtil.java

@@ -22,6 +22,7 @@
 import com.google.cloud.datastore.telemetry.TraceUtil.SpanContext;
 import io.grpc.ManagedChannelBuilder;
 import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanBuilder;
 import io.opentelemetry.api.trace.Tracer;
 import io.opentelemetry.api.trace.TracerProvider;
 import java.util.Map;
@@ -115,6 +116,10 @@ public TraceUtil.Span startSpan(String spanName, TraceUtil.SpanContext parentSpa
     return new Span();
   }
 
+  public SpanBuilder addSettingsAttributesToCurrentSpan(SpanBuilder spanBuilder) {
+    return getTracer().spanBuilder("TRACING_DISABLED_NO_OP");
+  }
+
   @Nonnull
   @Override
   public TraceUtil.Span getCurrentSpan() {

google-cloud-datastore/src/main/java/com/google/cloud/datastore/telemetry/EnabledTraceUtil.java

@@ -238,7 +238,8 @@ public Scope makeCurrent() {
   }
 
   /** Applies the current Datastore instance settings as attributes to the current Span */
-  private SpanBuilder addSettingsAttributesToCurrentSpan(SpanBuilder spanBuilder) {
+  @Override
+  public SpanBuilder addSettingsAttributesToCurrentSpan(SpanBuilder spanBuilder) {
     spanBuilder =
         spanBuilder.setAllAttributes(
             Attributes.builder()

google-cloud-datastore/src/main/java/com/google/cloud/datastore/telemetry/TraceUtil.java

@@ -22,6 +22,7 @@
 import com.google.cloud.datastore.DatastoreOptions;
 import io.grpc.ManagedChannelBuilder;
 import io.opentelemetry.api.trace.Span;
+import io.opentelemetry.api.trace.SpanBuilder;
 import io.opentelemetry.api.trace.Tracer;
 import java.util.Map;
 import javax.annotation.Nonnull;
@@ -144,6 +145,12 @@ interface Scope extends AutoCloseable {
    */
   Span startSpan(String spanName, SpanContext parentSpanContext);
 
+  /**
+   * Adds common SpanAttributes to the current span, useful when hand-creating a new Span without
+   * using the TraceUtil.Span interface.
+   */
+  SpanBuilder addSettingsAttributesToCurrentSpan(SpanBuilder spanBuilder);
+
   /** Returns the current span. */
   @Nonnull
   Span getCurrentSpan();